import json
from collections import Counter
def  load_vacancies(filepath: str) -> list[dict]:
    try:
        with open(filepath,"r") as file:
            return json.load(file)
    except:
        print()    
        return []
def filter_by_city(vacancies: list[dict], city: str) -> list[dict]:
    return [i for i in vacancies if i.get('city','').lower() == city.lower()]
def filter_by_skills(vacancies: list[dict], required_skills: list[str]) -> list[dict]:
    return [i for i in vacancies if all(skill.lower() in set(k.lower() for k in i.get('skills')) for skill in required_skills ) ]
def filter_by_salary(vacancies: list[dict], min_salary: int) -> list[dict]:
    return [v for v in vacancies if v.get('salary_to') and v.get('salary_from') and v.get('salary_to')>= min_salary and v.get('salary_from')> min_salary]
def extract_unique_companies(vacancies: list[dict]) -> list[str]:
    return list({v.get('company') for v in vacancies if v.get('company')})
def extract_top_skills(vacancies: list[dict], top_n: int) -> list[tuple[str, int]]:
    all_skills = []
    for v in vacancies:
        all_skills.extend(v.get('skills', [])) 
    skill_counts = Counter(all_skills)
    return skill_counts.most_common(top_n)
def calculate_average_salary(vacancies: list[dict]) -> float:
    if not vacancies:
        return 0.0
    else:
        salaries = []
        for v in vacancies:
            salary_from = v.get('salary_from')
            salary_to = v.get('salary_to')          
            if salary_from is not None and salary_to is not None:
                salaries.append((salary_from + salary_to) / 2)
            elif salary_from is not None:
                salaries.append(salary_from)
            elif salary_to is not None:
                salaries.append(salary_to)        
        if not salaries:
            return 0.0       
        return sum(salaries) / len(salaries)
def group_by_company(vacancies: list[dict]) -> dict[str, int]:
    all_company = []
    for v in vacancies:
        all_company.append(v.get('company'))
    company_count = Counter(all_company)
    return company_count
def format_vacancy_short(vacancy: dict) -> str:
    salary_from = vacancy.get('salary_from')
    salary_to = vacancy.get('salary_to')  
    if salary_from is not None and salary_to is not None:
        salary_str = f"от {salary_from} до {salary_to}"
    elif salary_from is not None:
        salary_str = f"от {salary_from}"
    elif salary_to is not None:
        salary_str = f"до {salary_to}"
    else:
        salary_str = "зарплата не указана"
    return (f"ID {vacancy.get('id')}: {vacancy.get('title')} в {vacancy.get('company')}, "
            f"{vacancy.get('city')} — {salary_str}\n")
def save_filtered_results(vacancies: list[dict], filename: str) -> bool:
    try:
        with open(filename,"w") as file:
            file.writelines(format_vacancy_short(x) for x in vacancies)
        return 0
    except:
        return 1
def main():
    main_list=load_vacancies(input("Write path for json:"))
    filered_vacancies = filter_by_city(main_list,input("Write city"))
    skils_list=[]
    for i in range(int(input("Write number of skills: "))):
        skils_list.append(input(f"Write №{i + 1} skill: "))
    filered_vacancies=filter_by_skills(filered_vacancies,skils_list)
    filered_vacancies = filter_by_salary(filered_vacancies,int(input("Write salary: ")))
    print("Уникальные компании: ", ", ".join(extract_unique_companies(filered_vacancies)))
    top_skills = extract_top_skills(filered_vacancies, 5)
    print(f"Топ-5 навыков:")
    for skill, count in top_skills:
        print(f"  {skill}: {count} вакансий")
    print(f"\nСредняя зарплата: {calculate_average_salary(filered_vacancies):,.0f} руб.")
    for company, count in group_by_company(filered_vacancies).items():
        print(f"  {company}: {count} вакансий")
    if(save_filtered_results(filered_vacancies,input("Write where to save"))):
        print("Check your path")
    else:
        print("Everything is fine, the file is saved")
if __name__ =="__main__":
    #вход проги 
    main()